Rubbish dealer and repeat engine fault codes

[chempsall]

Hi,

I have a 2009 Chevrolet Taho Z71.

I live in Doha, Qatar, where unfortunately the dealer support is not good (I'm trying very hard to be polite here!).

I have had a repeat problem with my Tahoe showing the engine fault light. It has been back to the dealer five times for them to attempt to fix it but the problem never goes away for more than a few days.

I have now borrowed a DiabloSport Predator to read the engine fault codes. They are P1133 and P1153.

The dealer's explanation for these problems has so far been:

1st visit - the car needed tuning and we've done that for you.

2nd visit - the car needed tuning and we've done that for you.

3rd visit - the problem is caused by "too much air" and that is because of the non standard air filter installed (it looks like a VR Tri-Power)

4th visit - the car needed tuning and we've done that for you. (I don't know what they did on this visit but now under low speed hard acceleration it makes a horrible noise - like pebbles in a metal biscuit tin!)

5th visit - the problem is caused because a previous owner removed the catalytic converter in the exhaust system.

I haven't got a clue if any of this could actually be true or not. Can anybody suggest some simple steps I can undertake myself to try and get to the bottom of the problem?

Thanks in advance for any assistance received.


Chris

 

[iwaslowr]

Here's some info from stevek in thread http://www.tahoeyukonforum.com/forum/showthread.php?t=11564

Does anybody have any clue what the possibilities are for this code? I know its a air/fuel mixture issue, but more specifically, what part is failing on me here most likely?

Do you have any other codes?

P1133

DTC P1133

CIRCUIT DESCRIPTION
Heated oxygen sensors (HO2S) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content in the exhaust stream. The HO2S must reach operating temperature to provide an accurate voltage signal. Heating elements inside the HO2S minimize the time required for the sensors to reach operating temperature. The powertrain control module (PCM) supplies the HO2S with a reference, or bias, voltage of about 450 mV . When the engine is first started the PCM operates in open loop, ignoring the HO2S voltage signal. Once the HO2S reaches operating temperature and closed loop is achieved, the HO2S generates a voltage within a range of 0-1,000 mV that fluctuates above and below bias voltage. High HO2S voltage indicates a rich exhaust stream; low HO2S voltage indicates a lean exhaust stream. This diagnostic will only run once per ignition cycle. The PCM monitors the number of rich-to-lean and lean-to-rich transitions. If the PCM detects that the number of transitions were less than a specified value, DTC P1133 sets for HO2S bank 1 sensor 1, or DTC P1153 sets for HO2S bank 2 sensor 1.

EDIT:
http://ww2.justanswer.com/uploads/Bluegorilla/2009-10-20_142801_2001_k_P1153_delphi.pdf

Check that out, gives you some help

Do you have catalytic converters installed on your exhaust just behind the manifolds?

 

[chempsall]

Hi,

Thanks a lot for replying. I thought I checked the box asking for email notifications when there was a new reply but obviously not. Sorry for taking so long to say thanks.

You asked me "Do you have catalytic converters installed on your exhaust just behind the manifolds" and the honest answer is I've got no idea what a catalytic converter even looks like. I've just spent half an hour searching google to get an idea but still don't know. Can you give me an idea?

If the catalytic converters aren't there (as the dealer has said) is there any way to get rid of this fault without buying some? (Remember I live in a place where I have more-or-less no chance of finding a guy who knows anything about engine tuning).

As for the horrible noise (like pebbles in a metal biscuit tin!) somebody has told me this is because the dealer hasn't tuned the car correctly. Whilst this wouldn't be a surprise does anyone know if this sounds reasonable?

Thanks,


Chris

 

[totheyard]

Hi,

Thanks a lot for replying. I thought I checked the box asking for email notifications when there was a new reply but obviously not. Sorry for taking so long to say thanks.

You asked me "Do you have catalytic converters installed on your exhaust just behind the manifolds" and the honest answer is I've got no idea what a catalytic converter even looks like. I've just spent half an hour searching google to get an idea but still don't know. Can you give me an idea?

If the catalytic converters aren't there (as the dealer has said) is there any way to get rid of this fault without buying some? (Remember I live in a place where I have more-or-less no chance of finding a guy who knows anything about engine tuning).

As for the horrible noise (like pebbles in a metal biscuit tin!) somebody has told me this is because the dealer hasn't tuned the car correctly. Whilst this wouldn't be a surprise does anyone know if this sounds reasonable?

Thanks,


Chris

Look for box like objects(bigger than the exhaust diameter) welded into the exhaust after the exhaust manifolds. One on each side. If its straight pipe/ hacked pipe, the it has been tampered with.

 

[chempsall]

Am I looking in the right place?

 

[NathanJax]

Those 4 tubes are part of your exhaust headers. once they go underneath your truck, they should go in to the catalytic converters. take a pic of those 4 tubes from underneath your truck and follow them back.

 

[InTruckDesign]

Those are some longtube headers, most likely you do not have cats in your exhaust system, and the rear O2 sensors most likely have not been turned off to not report to the ecm hence the DTC P1133, 1153.
As for the noise of (like pebbles in a metal biscuit tin!) it is probably related to pinging or detonation due to an improper pcm tune to adjust for the aditional airflow created by the cai and headers.
Good luck finding a good tuner, maybe look at purchasing an Autocal by EFI Live and have the ability to datalog and email them to a tuner back here in the States, then they could email a tune to you and you can dowload it into the truck...I would highly recommend BlackBear Performance who is also a supporting vendor on this site.

 

[domin8]

I agree with utilizing Black Bears services for tuning.

 

[Goodinblack]

Looks like he has duals too according to the first pic.

 

[chempsall]

Hi,

I crawled under the car this weekend and managed to get the attached picture. This is the only thing bigger than the exhaust diameter I can find.


Chris